Method and apparatus for shipboard storage and refrigeration of freshly caught fish



May 2, 1961 A M. J. PURETIC 2, 82,10

METHOD AND APPARATUS FOR SHIPBOARD STORAGE AND REFRIGERATION OF FRESHLYCAUGHT FISH 2 Sheets-Sheet 1 Original Filed Dec. 16, 1957 firsurok4rram/sy.

May 2, 1961 M. J. PURETIC METHOD AND APPARATUS 2,982,109 FOR SHIPBOARDSTORAGE AND REFRIGERATION 0F FRESHLY CAUGHT FISH 16, 1957 2 Sheets-Sheet2 Original Filed Dec.

"sun, a serious health hazard is presented.

occurrence of heart attacks, sometimes fatal, is a com- U d SW Pa n iMETHOD AND APPARATUS FOR SHIPBOARD STORAGE AND REFRIGERATION 0F FRESHLYCAUGHT FISH Mario J. Puretic, 30514 Avenida Corana, San Pedro, Calif.

"Continuation of application Ser. No, 702,868, Dec. 16, .1957. Thisapplication May 12, 1960, Ser. No. 28,805

7 Claims. or. 62-64 This is a continuation'of my co-pending patentapplication, Serial No. 702,868filed December 16, 1957, and nowabandoned.

The present invention relates generally to the field of commercialfishing, and more specifically to a novel' method and apparatus forstoring and refrigerating fresh- 1y caught fish on board ship.

Heretofore there have been two generally accepted method'sused forstoring and refrigerating fish aboard a commercial fishing boat.According to one method the fish are stacked in storage bins with layersof chopped icejinterspersed between the layers of fish. After a periodof storage it may be necessary to replenish the ice in order to maintainrefrigeration of the fish.

' The other method which has been commonly used is that of immersing thefish in cold brine. According to this method the fish are stored in atank filled with brine, and the temperature of the brine is kept down tothe desired level by contact with the cooling pipes of a refrigeratingsystem.

, The useful cargo space heretofore available for carrying fish hasbeenseriously limited as a direct result of the antiquated methods ofstoring and refrigerating the fish. That is to say, the methodsheretofore used have wasted much of the cargo space which could havebeen available for fish storage. Also, the time requirements have beenexcessive, in preparing the fishing boat before it"leaves its home base,in loading the fish onto the boat as they are caught,iand in unloadingthe catch when the boat returns to port. L

The methods heretofore used have also made excess'ive demands upon thecr'ewme'mbers who have per formed the work of loading the fish.Experienced men are required for handling fish packing operations in thefreezer holds where chopped ice is used for refrigeration. Handling thechopped ice and heavy fish in tempera: tu res'of about zero degreesFahrenheit involves hard labor, and when the worker returns tothe boatdeck where the air temperature may be from 80 to 100 Fahrenheit, andwhere he may also be exposed to the In fact, the

monplace result of working under these conditions.

Excessive spoilage of the fish, as well as physical damage. incurred inthe-handling 1 process, have also resultedfrom the methods heretoforeused In the icepack method of'storage the excellent insulatingpropertiesof the ice preclude an even temperature distribution and makeit possible for the fish to become toowarm, at'least in certain portions"of the fish hold, despite the fact that alarge quantity of ice isstillpresentin the fish hold In "other words, with theaice-packmethod thetemperature is not equalized well'e nough to insure goodi-"e'f'rigeratio-n. Furthermore, with theJice-packmefhOd there is alwaysthe danger ofrun'n'ing'out Mice, with resultant spoilage of the fish,which 'o ften makes it necessar'y for the boat'toreturn 'to port withonly a partial during the packing of the load, and to an even greaterextent during the unloading process since it is conventional practice touse ice picksto loosen the pack and Furthermore, the tanksful of coldbrine constitute a very proved method of storing and refrigerating fishwhich heavy load which isa menace to navigation and greatly provide animproved method for storing and refrigerat ing freshly caught fishaboard a commercial fishing boat.

Another object of the invention is to provide an immakes fullutilization of the cargo'space of the fishing boat, saves time andlabor, and minimizes spoilage as well as physical damage to the fish.

A further object of the invention is to providenovel apparatus forstoring and cooling freshly caught fish on 'a commercial fishing boat. IV

According to the present invention a fish hold is utilized whichincludes a substantially horizontal grill structure dividing the holdinto upper and lower por-' tions. Freshly caught fish are stacked uponthe grill structure within the'uppe'r portion of the hold, and a liquidcoolant such as cold brine is sprayed upon the fish from a number ofseparate spraying positions near the top of the hold. As the liquidcoolant drips through the fish'stack into thelower portion of the fishhold, it is pumped out of the hold, circulated through a nearbyrefrigerating system, and returned to the spraying positions,.in acontinuous operating cycle.

Additional objects of the invention, therefore, are to provide a methodof storing freshly caught fish such that they may be convenientlysprayed with a liquid coolant without the necessity of completeimmersion in a liquid bath; to provide a liquid spray method of coolingfreshly caught fish; and to provide a method and apparatus formaintaining refrigeration of a cargo of fish after the storage andinitial cooling thereof.

The. above and other objects of the invention will be more readilyunderstod from the following description iii conjunction with theaccompanying drawing, in which:

Figure in an elevational view partially in section, of a fishing boatembodying the present invention;

Figure 2 is a cross-sectional view of the fish hold of the boat ofFigure 1 showing how a cargo of fish is" stored therein;

Figure 3 illustrates the spraying system utilized in the fishing boat ofFigure 1;

Figure 4 illustrates the refrigerating system 'of Figure 1, togetherwith suitable apparatus for recirculating and cooling the liquidcoolant; V

Figure 5 illustrates one form of spray nozzle;

Figure 6' illustrates a section of seeper hose; and I Figure7illustrates another form of spray nozzle.

; 1Referring generally to Figures 1-4.of the drawings; a"

'fish'hold 20 of the boat. .A substantially horizontal grill structure21 near the bottom of the fish hold divides the hold into antupperportion 22 and a lower portion 23; Liquid coolant .18 iscontinuouslysprayed fro'r'nfa' i spraying systni iatl ontotheload offish which has been stacked upon grill 21 in upper portion 22 of thehold 20. Liquid coolant drips through the stack of fish and collects inlower portion 23 of the hold, and is then pumped to a refrigeratingsystem 50 where it is-cooled and recirculated back into the sprayingsystem;

Fish hold 20 is illustrated as having the sides thereof defined by thehull 12 of the vessel, andthe top or-celling thereof defined by the boatdeck 13. A batch 24 in deck 13 provides an opening through which thefish may be loaded or unloaded from the hold.

Spraying system 30 includes a liquid supply conduit 31 which feeds intoa pair of conduits 32 and 33 controlled by manually operable valves 32aand 33a, respectively. Conduit 32 is connected to a pair of additionalconduits 34 and 35 controlled by valves 34a and 35a, respectively, thethree conduits 32, 34 and 35 being positioned substantially in' ahorizontal plane and running parallel to each other longitudinally ofthe fish hold 20 near the top of upper portion 22 thereof. Conduit 34supplies liquid coolant to a plurality of spray nozzles 36a, 36b, etc.;conduit 32 supplies a string of spray nozzles 37a, 37b, 37c, etc.; andconduit 35 supplies a string of spray nozzles 38a, 38b, etc. All of thespray nozzles are adapted to spray the liquid coolant downwardly uponthe load of fish stacked in hold 20.

Conduit 33 of the spraying system supplies liquid coolant to conduits 39and 40 controlled by valves 39a and 40a, respectively. Seeper hoses 41a,41b and 410, lying substantially in a horizontal plane and runningparallel to each other longitudinally of the fish hold 20, receiveliquid coolant from conduits 39, 33 and 40,'respectively.

'As will be readily understood, the present invention is not limited toa fish hold of any particular size or shape, so long as a grillstructure is provided therein for supporting the fish and for permittingthe liquid coolant to drip through into the lower portion of the holdfrom whence it may be recovered and recirculated. While the seeper hosesas illustrated are useful in supplying liquid coolant to the interiorportion of a large stack of fish, it will be understood that for asmaller cargo such seeper hoses would be unnecessary and the job couldbe accomplished by means of spray nozzles only. In any event, it is thepurpose and intent of the present invention to continuously supplyliquid coolant to the cargo of fish in a sprayed or dispersed form suchthat the air spaces within and surrounding the cargo of fish arecontinuously kept cold and humid, and that each individual fish of thecargo is continuously provided with a liquid coating covering asubstantial portion of its exterior surface.

The reasons Why the present inventfon provides many advantages hithertounavailable may be summarized as follows. Continuous spraying of theliquid coolant insures continuous evaporation, and hence the cooling ofall of the open spaces in the fish hold. The high humidity in the openspaces of the hold provides a much greater heat conductivity than couldbe obtained from a dry air space and hence establishes a uniformtemperature and rapid cooling action. High humidity of the air spaces isalso advantageous in that it prevents dehydration of the fish such asoccurs, for example, in the ice-pack method of storage.

When freshly caught fish are first stored in the hold it is necessarythat the heat be removed from thernwith suflicient rapidity to forestallspoilage. A continuous flow of liquid coolant which 'comes in contactwith a substantial portion of the surface of each fish provides'as muchcooling capacity as could be obtained by any previously known method.This is so because the carrying away of the heat from the fish is notdependent upon the .fiow of heat through a body of liquid, as in thecold brinev method of storage,,but.rather is accomplished by the flow ofthe liquid. itself which occurs'in a continuous and rapid manner inresponse to the ever-present force of gravity., Thus,fduring theinitial'cooling'of the fish after the catch; has been stored inthe hold,therate at which the cooling takes place can be established at anydesired value simply by recirculating liquid coolant at a sufiicientlyrapid rate and providing a refrigerating system of sutficient capacityfor cooling the liquid coolant as it is recirculated. t

In carrying out the present invention it is convenient to utilize as theliquid coolant a brine solution which consists of ocean water as takendirectly from the ocean or in a modified form. The undesirable effectsof salt penetration into the fish cargo which occurs in the cold brinemethod of storage are substantially eliminated by the present invention.In the cold brine method of storage, the occurrence of salt penetrationinto the fish is largely a result of the fluid pressure of the brine inthe fish tank. According to the present invention the fish are notimmersed in the liquid coolant bath, hence the fluid pressure at theexterior surface of each fish is limited to the atmospheric pressure.

Continuing now with the decription of the apparatus as illustrated inthe drawings, a return conduit 60 positioned in lower portion 23 of thefish hold 20 is connected to a collector pump 52 which collects therelatively warm liquid coolant and pumps it through a conduit 53 intothe upper portion of a cooling tank 51. A plurality of cooling pipes 57positioned within cooling tank 51 are coupled to a refrigeratorcompressor 58 which circulates a refrigerant through the cooling pipes.After the liquid coolant has been cooled by passing through tank 51, itis drawn through a conduit 59 by a pump 54 and is continuously suppliedto the spraying system 30 via conduit 31.

Conduit 53 empties the warm or used liquid coolant into the upperextremity of tank 51, where it falls on the upper surface of a filteringscreen 55. Screen 55 is inclined at an angle with its upper end adjacentinlet conduit 53, so that the liquid coolant runs down the surface ofthe screen while simultaneously filtering through. Means, not shown, arepreferably provided for periodically cleaning the filter screen. In thismanner accumulations of blood and other organic material may be removedfrom the cooling system. Not only are the fish protected againstspoilage, therefore, but the cargo when delivered to port is in a cleanand wholesome condition.

A temperature gauge 62 is mounted on conduit 53 thus permittingcontinuous observation of the temperature of the relatively warm liquidcoolant as it is pumped from the hold. Another temperature gauge 63 onconduit 31provides a continuous indication of the temperature of therefrigerated coolant being supplied to the spraying system. Operation ofthe system can then be controlled by varying the rate at which theliquid coolant is recirculated, or by controlling the refrigeratorcompressor to increase or decrease its effective output, or both.

In Figure 6 of the drawings there is illustrated a portion of a seeperhose 42 which may be satisfactorily used in carrying out the presentinvention. Hose 42 has a number of openings 42a, 42b, etc. spacedthroughout its length for dispensing the liquid coolant thcrethrough.

In Figure 5 is illustrated a spray nozzle 44 which may be utilized incarrying out the present invention. Mounted upon the upwardly disposedthreaded end of a conduit 44a, nozzle 44 includes an inverted cup 44bhaving internal threads (not shown) and having exterior flanges 44c,44c,which may be grasped for loosening it or tightening thenozzle uponthe conduit. A horizontal slot 44d extending partially around the cup44b provides an opening through which the liquid coolant emerges in aspray or other dispersed configuration.

In Figure 7 there is illustrated another form of spray nozzle which maybe utilized in the present invention. Thus, the nozzle 43 includes afixture 43a engaging the threaded upwardly disposed end of a conduit 43bfor projecting a stream of the liquid coolant vertically upasset-es":

wardlywhere it strikes the under surface of a deflection housing 430.Deflection housing 43c is in the form of a hollow cone whose vertexdefines an obtuse angle. Deflection housing 430 is rigidly supported byribs 43d, 43d, each of which interconnects a point on the lower rim ofthe deflection housing with member 43a.

Although the form of my invention above described in detail is fullycapable of achieving the results and providing the advantageshereinbefore mentioned, it is to be understoodthat it is merely thepresently preferred embodiment thereof, and that I do not mean to belimited to the details of construction above described other than asdefined in the appended claims.

-I-claim: a

1. Apparatus for cooling and storing freshly caught fish in the hold ofa ship, comprising: substantially horizontally extending grill meansdisposed in the lower portion of said hold, the space in said holdabovesaid grill means defining a fish-receiving chamber and the space belowsaid grill means defining a liquid refrigerant-receiving chamber; a bodyof liquid refrigerant having a volume equal to or less than the volumeof said liquid refrigerant-receiving chamber; conduit means for saidliquid refrigerant extending through said fish-receiving chamber; spraynozzles on said conduit means that direct said liquid refrigerant ontofish disposed within said fish receiving chamber; a refrigerating systemon said ship .that receives said liquid refrigerant and reduces the heatcontent thereof to a value required for preventing spoilage of saidfish; pumping means that force said'liquid refrigerant from said liquidrefrigerant-receiving chamber through said refrigerating system and saidspraying means; and a plurality of apertured flexible conduits extendingthrough said fish-receiving chamber below said below said grill meansdefining a liquid refrigerant-receiving chamber; a body of liquidrefrigerant having a volume equal to or less than the volume of saidliquid refrigerant-receiving chamber; conduit means for said liquidrefrigerant extending through said fish receiving chamber; spray nozzleson said conduit means that direct said liquid refrigerant onto fishdisposed within said fishreceiving chamber; a refrigerating system onsaid ship that receives said liquid refrigerant and reduces the heatcontent thereof to a value required for preventing spoilage of saidfish; pumping means that force said liquid refrigerant from said liquidrefrigerant-receiving chamber through said refrigerating system and saidspraying means; a plurality of apertured flexible conduits extendthroughsaid fish-receiving chamber below said first-mentioned conduit meansthat supply said liquid refrigerant into spaces defined between fisharranged within said fishreceiving chamber; and filtering means disposedin the path of said liquid refrigerant to remove organic mate rialfrom's'aid liquid refrigerant.

3. Apparatus for cooling and storing freshly caught fish in the'hold ofa ship, comprising: substantially horizontally extending aperturedfish-supporting means'disposed in the lower portion of said hold, thespace in said hold above said fish-supporting means defining afishreceiving chamberandthe space below said fish-supporting meansdefining a liquid refrigerant-receiving chamber; a body of liquidrefrigerant having a volume equal to or less than the volume of saidliquid refrigerantreceiving chamber; main spraying means'within saidhold thattdirectisaid liquid refrigerantover the upper portion 0f fish,"arranged within said fish-receiving chamber; 1 auxiliary spraying meanswithin said hold that direct saidliquid refrigerant th eu h the 'spacessepai'atihg the iiiing chamber through said refrigerating system andsaid main and auxiliary sprayng means.

4. Apparatus for cooling and storing freshly caught fish in the hold ofa ship, comprising: substantially'horizontally extending aperturedfish-supporting means disposed in the lower portion of said hold, thespace in said hold above said fish-supporting means defining afishreceiving chamber and the space below saidfish-supporb ing meansdefining a liquid refrigerant-receiving chamber; a body of liquidrefrigerant having a volume equal to or less than the volume of saidliquid refrigerant-receiving chamber; main spraying means within saidhold that direct said liquid refrigerant over the upper portion of fisharranged within said fish-receiving chamber; auxiliary spraying meanswithin said hold that direct said liquid refrigerant through the spacesseparating the individual fish arranged within said fish-receivingchamber, said auxiliary spraying means being disposed below said mainspraying means means and extending between the spaces separating saidindividual fish; a refrigerating system onsaid ship that receives saidliquid refrigerant and reduces the heat content thereof to a valuerequired for preventing spoilage of said fish; pumping means that forcesaid vmeans disposed in the lower portion of said hold, the

space in saidhold above said fish-supporting means defining afish-receiving chamber; a body of liquid refrigerant having a volumeequal to or less than the volume of said hold; main spraying meanswithin said hold that direct said liquid refrigerantrover the uppersurfaces of a body of fish arranged within said hold; auxilairy sprayingI means within said hold below said main spraying means,

said auxiliary spraying means directing said liquid refrigerant throughthe spaces between the fish arranged within said hold; a refrigeratingsystem on said ship that receives said liquid refrigerant and reducesthe heat content thereof to a value required for preventing spoilage ofsaid fish; conduit means connecting the lower portion of said hold withsaid refrigerating system; and pumping means in communication with saidconduit means that force said liquid refrigerant from said hold, throughsaid refrigerating system and throughsaid main and auxiliary sprayingmeans. 7 l

6. Apparatus for cooling and storing freshly caught fish in the 'holdof'a ship, comprising: fish-supporting means disposed in the lowerportion of said hold, the space in said hold above said fish-supportingmeans defining a fish-receiving chamber; a body of liquid refrigeranthaving a volume equal to or less than the volume of said hold; mainspraying means within said hold that direct said liquid refrigerant overthe upper surfaces of refrigerant through the spaces between the fisharranged within said hold; a refrigerating system on said ship thatreceives ,said liquid refrigerant and reduces the heat content thereofto a value required for preventing spoilage of, said fish; conduit meansconnecting the lower 'portion of said hold with said refrigeratingsystem; pumping means in communication with said conduit means thatforce said liquid refrigerant from said hold through said refrigeratingsystem and through said main and auxiiiary spraying means; and filteringmeans disposed in the path of said liquid refrigerant to remove organicmaterial from said liquid refrigerant.

7. A method of cooling and storing freshly caught fish in the hold of aship by means of a plurality of liquid refrigerant dispensing means thatincludes: arranging a first layer of said fish in a fish-receivingchamber of said hold; disposing a portion of said liquid refrigerantdispensing means in physical contact with said first layer of fish;spraying liquid refrigerant over said first layer of fish by means ofsaid portion of said liquid refrigerant dispensing means; arranging asecond layer of fish in said fishreceiving chamber above said firstlayer of fish;

spraying refrigerant over the upper surfaces of said sec-.

for subsequent spraying over said fish in a continuousrecirculatingcycle.

References Cited in the file of this patent UNITED STATES PATENTS1,894,813 Zarotschenzefi Jan. 17, 1933 1,947,327 .Brettell Feb. 13, 19342,746,272 Carpenter May 22, 1956.

